More than one in five ponds in the UK could be designated as “priority habitats” but only about 2% have been identified so far, experts say.

Priority ponds are recognised as being the highest-quality water spaces for freshwater wildlife, often providing a last refuge for plants and animals that have been lost from surrounding areas. The designation can help preserve ponds threatened by proposed construction and other landscape changes.

Because so many of these water bodies go under the radar, the Freshwater Habitats Trust (FHT) is asking citizen scientists to help identify what could make up more than 20% of Britain’s existing ponds.